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TEMPERATURE CYCLING EFFECTS ON BACTERIAL GROWTH. 1. Pseudomonas fluorescens
Author(s) -
HOWELL A. J.,
SAFFLE R. L.,
POWERS J. J.
Publication year - 1971
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1971.tb03304.x
Subject(s) - pseudomonas fluorescens , cycling , temperature cycling , bacterial growth , constant (computer programming) , pseudomonas , atmospheric temperature range , chemistry , temperature gradient , bar (unit) , bacteria , food science , biology , thermal , thermodynamics , genetics , physics , archaeology , quantum mechanics , meteorology , computer science , history , programming language
SUMMARY –Although temperatures occurring in nature are constantly fluctuating, virtually all research involving temperature effects on organisms has been carried out at constant temperatures. An investigation was made to determine the effect mild cycling of temperature has on certain species of bacteria. The effect of constant and cycled‐up or cycled‐down temperatures was determined for Pseudomonas fluorescens. A thermal gradient‐bar proved to be a rapid, efficient method for determining these effects, affording a wide range of temperatures with only a few degrees difference between two consecutive temperatures. Cycling effects appeared to be dependent upon the organism and whether or not the temperature was above or below the optimum growth temperature. In general, the cycled‐down growth responses appear to be greater than those for the cycled‐up responses. At temperatures both above and below the optimum, the cycled‐down organisms produced greater growth responses than the cycled‐up organisms. The constant values are only a small amount greater than the cycled‐down values.